Injection pump for internal combustion engines



' Nov. 26, 1940. M. VHURST EI'AL INJECTION P UMP FOR INTERNAL COMBUSTION ENGINES Filed Jun e so, 1939 2 SheefQ s-Sheet 1 I ITlVn Fur Max Hurst 0 170 Beck 1 R61 Nov. 26, 1940. M. HURST EI'AL INJECTION PUMP FOR INTERNAL COMBUSTION ENGINES Filed June 30, 1939 2 Sheets-Sheet 2 vv nhns Huvsf Om yank 1 R 7 Patented Nov. 26,

UNITED. STATES INJECTION PUMP roe INTERNAL COMBUSTION enemas Max Hurst, Stuttgart, and Otto Beck, Winterb'ach O/A Schorndorf, Germany, assignors to Robert Bosch Gesellschaft mit beschriinkter, Haftung, Stuttgar Germany Application June 30, 1939, Serial No. 282,260 In Germany July 30, 1938 18 Claims.

The invention relates to injection pumps for internal combustion engines of the type in which a piston is axially displaced within a cylinder to provide a pumping effect and can be rotated in individual adjustments of the fuel supply condi tions of each separate cylinder may be effected.

A further object is to enable such an arrangement to be operated without the necessity of wholly or partially disassembling the pumps.

A still further object is to permit of adjustment by means of relatively simple tools, and

without waste of time.

Other objects and advantages will become apparent in the following description of the invention, with reference v to the accompanying drawings in which:

Figure-1 shows one form of construction, in section, at right angles to the driving shaft.

Figure 2 illustrates parts out of Figure 1 shown in perspective.

Figure 3 shows a further form of construction, in section, at right angles to the driving shafts.

Figure 4 illustrates parts out of Figure 3 shown in the same manner as those in Figure 2.

In a housing I of. a separate pump, a plunger '4 is moved by a cam 2' through a cam-follower 3. The fuel supply, or alternatively, the return flow of fuel, is adjusted in known manner by rotative displacement of apistonj, with consequent adjustment of the position of a helical edge 5 of the piston in a cylinder 9. A diagonal toothed rod 1 common to allthe pumps, is guided in the pump housing I and engages with a toothed quadrant forming part of a collar 9a of the intermediate membr 9, which is fitted over the cylinder. The member 9 is provided with vertical slots ill at the end directed towards the drive.

These slots-receive projections ll of the piston 4.-

through the housing I. -The projectionit en gages in a groove ll inthe periphery of the collar to. The pin can be locked in any desired position by means of' a threaded ring I! and a sealing washer l9 which rests on a shoulder l9 of the pin l5.

Normally the fuel supply is uniformly adjusted for all the pumps by the displacement of the toothed rod I which causes the operating sleeves, 9 to rotate all the pistons l by means of the coupling projections Ii. If the fuel delivery of an individual pump is to be adjusted in relation. to the other pumps, this is effected by angular displacement of the pin l5 after loosening the thread ring it. This rotary movement of the pin it causes the eccentric projection It to rise or fall, carrying with it the control sleeve 9 with which it engages. On account of.the diagonal toothing of the segment 8 which engages with the toothed rod 1, this axial displacement causes the intermediate member 9 to be rotated, thus causing angular displacement of the piston. When the iston has been adjusted so as to produce the desired alteration in the fuel delivery, the pin l5 is tightly locked in its new position in the housing by tightening the threaded ring I8.

The example of construction shown in Figure 3 differs from the first in that instead of the adjusting pin, a universally adjustable spindle 29 is disposed in a bore running parallel to the axis of the piston. That end of the bore 20' which is remote from the drive is provided with a thread 29 to receive the threaded part 21 of the head of a spindle. A threaded locking ring 28 at the upper end serves to secure the spindle in the position into which it is adjusted from without. A screw cap 29 seals the end of the bore 20'. On that end of the spindle 20 which is turned toward the drive is fitted a sliding-plate 2| which is angularly displaceable but not axiallydisplaceable in relation to the spindle. This sliding-plate 2i engages in a groove I'l in a partially toothed collar 22. Both the toothed collar and the rod 1' have vertical teeth,-in contrast to the diagonally toothed engagement between I and 9 of Figure 1. The hub of the toothed collar 22 is provided with diagonally directed grooves 23 which engage with complementary ridges 24 on the sleeve 9'. That end of the sleeve which is remote from the drive rests on a shoulder 25 of the housing, thus securing the sleeve against longitudinal displacement. That end of the spring I2 which is remote from the drive abuts against an annular spring plate 30, the end surface of which rests against a a shoulder 32 of the housing I.

By the adjustment of the spindle 20 the toothed collaris axially displaced by the sliding-plate 2i with the result that the sleeve 9' is annularly displaced together with the piston. The adjustment 5 of fuel supply is eifected in the same manner as in the flrst example (of construction.

' 'The hub of the toothed collar 22 can be provided with diagonally directed ridges instead of grooves, which ridges engage in complementary grooves or slots in the sleeve 9'. Instead of the spindle an eccentric pin engaging in a groove may be used in this form of construction as in Figure 1.

In the examples shown, the adjustment of fuel supply from without, by means of the eccentric pin or the spindle, merely alters the conclusion of fuel injection of-the individual pump in question, in relation to the other pumps, because that edge of the piston which regulates the commencement of fuel injection lies in a plane at right angles-to the axis of .the piston. Ii this edge of the piston were also a diagonal edge and if it were parallel to the diagonal edge controlling the conclusion of injection, then the adjustment devices as described would eflect an adjustment of the commencement of injection without affecting the amount of fuel delivered by the pump in question, in relation to the other pumps. In this case the displacement of the governor rod would simply eifect a uniform adjustment of the commencement of injection of all the pumps.

However, if the two diagonal edges corresponding to commencement of injection and conclusion of injection are not parallel, then adjustment either through the governor rod or through the adjustment device will result in an alteration of the amount of fuel delivered and of the commencement of injection.

We declare that what we claim is:

1. A fuel injection pump for internal combustion engines comprising in combination a housing, a cylinder disposed in said housing and providedwith inlet and outlet openings, a piston,

provided with valve means cooperating with said openings, axially displaceable within the cylinder to provide a pumping eil'ect and rotatively displaceable relative to the cylinder to control the pumping effect, an intermediate member disposed with the piston and rotatively to displaceable therewith, a control rod in geared relationship with said intermediate member whereby the intermediate member and piston may i be rotated by means of a displacement of the control. rod, means'whereby axial displacement of the intermediate member relatively to the cylinder provides a rotative displacem t of the piston without displacement of the co trol rod, and means for axially adjusting the position of the intermediate member.

2. A fuel injection pump for internal combustion engines comprising in combination a housing, a cylinder disposed in said housing and provided with inlet and outlet openings, .9. piston, provided with valve means cooperating with-said openings,

o5 axially displaceable within the cylinder to provide a pumping efl'ect and rotatively displaceable within the cylinder to control the punip'ing effect, an intermediate member consisting of two elements disposed coaxially with the piston, of which the 70 first element is adapted for eng'agement with the Piston so as -t o be rotatively displaceable therewith and is arranged toiengage the second element so that a relative longitudinal displacement I of the two elements produces a dependent rela- 75 tive rotative displacement; a control rod in geared 3. A fuel injection 'pump for internal co'mbustion engines comprising in combination a housing,

' a cylinder disposed in said housing and provided with inlet and outlet openings, a piston, provided with valve means cooperating with said openings, axially displaceable within the cylinder to provide a pumping efiect and rotatively displaceable within the cylinder to control the pumping effect, an intermediate member consisting of two elements disposed coaxially with the piston, of which the first element is adapted for engagement with the piston so. as to be rotatively displaceable therewith and is arranged to engage the second element through diagonal claw couplings formed on complementary faces of the elements so that a relative longitudinal displacement of the two elements produces a dependent relative rotative displacement, a cbntrol rod in geared relationship with the second element of the intermediate member whereby the intermediate member and piston may be rotated by means of a displacement of the control rod, and means for axially adjusting the positions of the elements of the intermediate member relatively to each other,

4. A fuel injection pump for internal combus-- one direction, a piston return spring for displacing the piston axially within the cylinder in the opposite direction; and intermediate member consisting of two elements disposed coaxially with the piston, of which the first element has two ends and is mounted outside the cylinder and is adapted for engagement with the piston so as to be rotatively displaceable therewith, and is arranged to engage the second element through diagonal claw couplings formed on complementary faces of the elements so that a relative longitudinal displacement of the two elements produces a dependent relative rot'ative displacement; a housing for the cylinder, a shoulder disposed within said housing so as to abut the first element of the intermediate member, a spring for urging that end of the first element more remote from the rotatable cam towards the shoulder, a

tion engines comprising in combination a housing,

a cylinder disposed in said housing and, provided with inlet and outlet openings, a piston, provided with valve means cooperating with said openings, r

axially displaceable within the cylinder to provide a pumping eflect and rotatively displaceable within the cylinder to control the pumping effect,

'7. An injection 'pump according to claim 6 5 which includes a diagonally toothed rod and a complementary diagonal toothing on the intermediate member.

8. An injection pump according to claim 1 wherein the means for axially adjusting the position of the intermediate member comprises a pair of substantially parallel surfaces disposed around part of the circumference of the intermediate member andan adjusting element engaging the intermediate member between the pair of surfacs.

9. An injection pump according to claim 1 wherein the means for axially adjusting the position of the intermediate'menrber comprises a pair of substantially parallel surfaces disposed around part of the circumference of the intermediate member and a pin passing throughthe housing and having an eccentric projection which engages the intermediate member between the pair of surfaces.

wherein the means for axially adjusting the position of the intermediate member comprises a pair of substantially parallel surfaces disposed around part of the circumference of the intermediate member, a pin passing through the hous' 'ing and having an eccentric projection at one end, and a sliding piece through which the eccentric projection of the pin engages the intermediate member between the pair of surfaces 5 aforesaid. I

11. An injection pump according to claim 1 wherein the means for axially adjusting the position of the intermediate member comprises a pair of substantially parallel surfaces disposed around part of the circumference of the intermediate member, a rotatable pin passing through the housing having an eccentric projection at one end which engages the intermediate member between-the pair of surfaces and having a circumferential shoulder disposed approximately at mid-length and a threaded member arranged for threadedly engaging the housing so as to be disposed coaxially with the pin and to abut the shoulder of the pin for locking said pin in any rotational position.

'12. An injection pump according to claim 1 wherein the meansfor axially adjusting the position of the intermediate member comprises a pair oi substantially parallel surfaces disposed around part of the circumference of the inter mediate member, an adjusting spindle disposed in the housing substantiallyparallel to the axis of the cylinder, and a sliding element attached to one end of thespindle and adapted for engagement with the intermediate member between the pair of surfaces.

13. An injection pump according to claim 2 wherein the means for axially adjusting the position of theintermediate member comprises a pair of substantially parallel surfaces disposed 10. An injection pump according to claim 1 .relativelv to each other.

around part of the circumference of the intermediate member, a rotatable pin-passing through the housing having an eccentric projection at one end which engages the intermediate member between the pair of surfaces and having a -cir cumferential shoulder disposed approximately at mid-length and a threaded member arranged for threadedly engaging the housing so as to be disposed coaxially with the pin and to abut the shoulder of the pin for locking said pin in any rotational position.

14. An injection pump according to claim 2 wherein the means for axially adjusting the position of theintermediate member comprises a pair of substantially parallel surfaces disposed around part of the circumference of the intermediate member, an adjusting spindle disposed in the housing substantially parallel to the axis to one end of the spindle and adapted for enof the cylinder, and a sliding element attached gagement with the intermediate member between the pair of surfaces.

15. A fuel injection apparatus for multioylinder internal combustion engines comprisingin combination a housing, a. plurality of pump cylinders disposed in said-housing and each provided with inlet and outlet openings, a piston provided with valve means cooperating-with said; openings, axially displaceable within each pump cylinder to provide a pumping effect and ro-'-' tatively displaceable to control the pumping effect of the cylinder, an intermediate member disposed coaxially with each piston and rotatively displaceable therewith, a common control rod in geared relationship with all the intermediate members whereby all the inter. lediate members and pistons may be rotated by means of a displacement of the control rod, means whereby axial displacement of any of the intermediate members relatively to the corresponding pump cylinder provides a rotative displacement of the corresponding piston without displacement of the control rod, and means for axially adjusting the'position of every intermediate member individually.

T 16. A fuel injection apparatus for multicylincoaxiallywith each piston, of each of which intermediate members the first element is adapted for engagement with the corresponding pis-' ton so as to be rotatively displaceable therewith and is arranged to engage the second element so that a relative longitudinal displacement of the two elements produces a dependent-relative. rotative displacement, a control rod common to all the; pump cylinders in geared relationship with each second element of the intermediate members whereby all the intermediate. members and pistons corresponding thereto may be rotated by means of a displacement of the control rod, and means for effecting separately axial adjustment of the positions of the respective elements of every individual intermediate member MAX HORST. 01'10 m 

